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FLASH GENE

Symbol

KCNJ2

contributors: mct/npt/pgu - updated : 20-12-2018

HGNC name	potassium inwardly-rectifying channel, subfamily J, member 2
HGNC id	6263

FLASH GENE DNA RNA EXPRESSION PROTEIN DISORDER ANIMAL & CELL MODELS

Corresponding disease	ATFB9 atrial fibrillation, familial, 9 PPKCA Andersen cardiodysrhythmic periodic paralysis SQT3 short QT syndrome-3
Location	17q24.3      Physical location : 68.165.675 - 68.176.181
Synonym name	inward rectifier K+ channel KIR2.1
	cardiac inward rectifier potassium channel
Synonym symbol(s)	IRK1, KIR2.1, HHIRK1, LQT7, HHBIRK1, HIRK1, ATFB9, SQT3

DNA

TYPE	functioning gene
STRUCTURE	10.51 kb     2 Exon(s)

10 Kb 5' upstream gene genomic sequence study

MAPPING

cloned

Y

linked

N

status

inconsistent : contradictory evidence

RNA

TRANSCRIPTS	type	messenger

identification nb exons type bp product Protein kDa AA specific expression Year Pubmed NM_000891 2 - 5397 NP_000882 - 427 - 1995 7590287

EXPRESSION

Type

expressed in	(based on citations)
organ(s)	System Organ level 1 Organ level 2 Organ level 3 Organ level 4 Level Pubmed Species Stage Rna symbol Cardiovascular heart         Homo sapiens Digestive intestine small intestine       Endocrine parathyroid         Respiratory respiratory tract larynx       Urinary kidney nephron

tissue

System Tissue Tissue level 1 Tissue level 2 Level Pubmed Species Stage Rna symbol Epithelial barrier/lining corneal epithelium     Epithelial sensory visual     Muscular striatum skeletal     Homo sapiens Muscular striatum cardiac     Homo sapiens

cells

System Cell Pubmed Species Stage Rna symbol Blood/Hematopoietic neutrophil Mus musculus Muscular myocyte Homo sapiens

cell lineage

cell lines

fluid/secretion

at STAGE

physiological period

pregnancy

Text

placenta

PROTEIN

PHYSICAL PROPERTIES

STRUCTURE

motifs/domains	two membrane-spanning domains
	an amphipatic region pore, including the P domain with the K+ channel signature
	an ATP-binding regulatory domain
	a PIP2 binding membrane-associated domain
	a cytoplasmic segment that is highly energetically unfavorable for cholesterol binding
	type I PDZ recognition motif at the extreme C terminus mediating interaction with all three PDZ domains of PSD-93delta

mono polymer

homomer , tetramer

HOMOLOGY

interspecies

homolog to murine MIrk1

Homologene

FAMILY

inward rectifier-type potassium channel family

CATEGORY

transport channel

SUBCELLULAR LOCALIZATION	plasma membrane
	intracellular
	intracellular,cytoplasm,organelle,membrane
	intracellular,cytoplasm,organelle,endoplasmic reticulum
	intracellular,cytoplasm,organelle,Golgi

basic FUNCTION	potassium voltage-gated channel, inwardly rectifying, playing a role in developmental signaling in addition to its function in controlling cell excitability in skeletal muscle and heart
	responsible for controlling membrane excitability in many cell types
	KCNJ2 and KCNJ12 are primary determinants of endogenous K(+) conductance in aortic endothelial cells under resting conditions and KCNJ12 provides the dominant conductance in these cells
	plays a critical role in modulating excitability by setting the resting membrane potential and shaping phase 3 of the cardiac action potential
	KCNJ2 and KCNJ12 have two distinct lipid requirements for activity: a specific requirement for INPP5J and a nonspecific requirement for anionic phospholipids
	participates in the maintenance of the cell membrane potential in a variety of cells including neurons and cardiac myocytes
	KCNJ2 channels are selected for export from the Golgi in a signal-dependent manner through an AP1 clathrin adaptor interaction
	normal KCNJ2 channel function is essential during osteoblastogenesis
	may participate in macrophage maturation and differentiation, and play a key role in lipid uptake and foam cell formation through modulating the expression of scavenger receptors.
	plays key roles in regulation of resting membrane potential and cell excitability

CELLULAR PROCESS

PHYSIOLOGICAL PROCESS

development

text	ion transport

PATHWAY

metabolism

signaling

a component

CDON forms a complex with KCNJ2 during myogenic differentiation, and is required for the channel activity by enhancing the surface expression of KCNJ2 in the early stage of differentiation

INTERACTION

DNA

RNA

small molecule

protein	multiple proteolytic pathways control KCNJ2 levels at the plasma membrane
	inhibition of KCNJ2 channels increases cell mobility without affecting cell cycling progression in human cardiac KIT progenitor cells
	STK39 and OXSR1 are both stimulators of KCNJ2 activity, and they are presumably effective by enhancing channel insertion into the cell membrane
	promyogenic CDON signaling is critical for KCNJ2 activities in the induction of myogenic differentiation

cell & other

REGULATION

activated by

hypoxic stress that up-regulates KCNJ2 expression and facilitates cell proliferation in brain capillary endothelial cells

inhibited by

powerful inhibitory effect of the AMP-activated kinase AMPK on the widely expressed inwardly rectifying K+ channel KCNJ2

Other	ATP regulated
	regulated by nitric oxide (NO) (under physiological conditions, NO regulates KCNJ2 through a redox-related process)
	is targeted for endoplasmic reticulum-associated degradation (ERAD)

ASSOCIATED DISORDERS

corresponding disease(s)

PPKCA , SQT3 , ATFB9

Other morbid association(s)

Type Gene Modification Chromosome rearrangement Protein expression Protein Function constitutional   translocation     non-syndromic Pierre-robin sequence may be caused by both SOX9 and KCNJ2 dysregulation in a patient with t(2;17) constitutional germinal mutation       cause a similar constellation of birth defects as in Fetal alcohol spectrum disorder (FASD), and alcohol targets likely KCNJ2 to cause the birth defects associated

Susceptibility

Variant & Polymorphism

Candidate gene
Marker	DUSP1 and KCNJ2 may be associated with mechanical asphyxia-induced death and can thus serve as useful biomarkers of death by mechanical asphyxia
Therapy target
	System Type Disorder Pubmed cardiovascular atheroma   may be a potential therapeutic target in the treatment of cardiovascular diseases, such as atherosclerosis and restenosis following percutaneous coronary intervention

ANIMAL & CELL MODELS